Typical baseballs (hardballs) and softballs comprise a solid core and two outer figure 8-type covers enclosing the core. The outer covers normally comprise two intersecting 8-shaped members, made of leather, the intersections of which are band stitched together by thread, to thereby envelop the core. A problem with conventional baseballs is that after the stitching operation, the thread stitching the two covers together is exposed. The threads become worn after usage, often to the point that the thread becomes broken. Once the threads become broken, the two covers start to separate from the core and the baseball becomes useless.
A further problem with conventional baseballs is that the stitches have wide variations in height and width due to difference in manufacturing materials and methods. These variations lead to nonuniform performance and longevity.
Traditional baseballs have used various methods to control stitch height and width. One method is to stitch damp leather, so that the stitches will be pulled tight when the leather dries. One obvious drawback of this method is that the stitch height and width is dependent on the material aspects of the leather used. Another technique is to constantly control the stitch tension while stitching dry leather. This technique suffers from the disadvantage of higher cost and it is also dependent on the leather used.
U.S. Pat. No. 5,772,544, granted Jun. 30, 1998, Yang, discloses a baseball or a softball which includes two or more cover members engaged on the outer portion of a core and having an abutting peripheral portion. A pad is engaged between the core and the abutting peripheral portion of the two cover members and is stitched and secured to the abutting peripheral portion of the cover members by a thread. When the thread is tightened, a number of bulges may be formed along the abutting peripheral portions of the cover members.
The thread becomes embedded in and protected by the bulges. Thus they are protected from being worn out easily.